yes i know what you think did i do the self test rigth yes i did i even took the truck to a auto shop. but any way i just replaced the air temp sensor or what ever you call it and the truck started fine but the CEL came on did the self test and no codes (light did not flash yes the light is good ) i didnt even give me the ok code 11 the auto shop didnt get any ether what could be the problem?

 

Did you run both KOEO and KOER tests?

Did you disconnect the battery for a while (15 minutes at least) after you replaced the ACT? Did the sensor you replaced have 1 or two wires?

What year model are we talking? ECM's started changing in '92, getting ready for EEC-V and OBD-II. I see '92 models in here with 3 digit codes, but know mine does 2-digit codes.

You want help, you gotta give us a little more info. We all know having a problem is irritating, and none of us likes to be treated like an idiot. We're intelligent enough to know when to ask for help. But your post will make some hesitant to offer help. It seethes with attitude and aggressiveness. You're here for free help. If we ask questions, it's to help us better understand your problem, and perhaps recognize a symptom, and hopefully lead you to a resolution. Since this is the first reply to your inquiry, and it certainly isn't an attack on your intelligence, why the attitude?

 

sry about that long hours make me forget to put inportant info in...ACT had 2 wires i did disconnect the bat for like 15 min and i have a 1990 f250 with a 351 w no attitude i just come off strong..atleast thats what my wife says.this truck has been prob after prob so i am also a littel fustrated befor i replaced the act sensor it gave codes to me fine but now it dont. sry for the lammness of my post. im just said all that to help eliminate some questions i get like does your CEL even work stuff like that

 

only thing i think it could be is that my smog pump is locked and i have it bypassed right now

 

sounds like the computer is bad to me but im just now getting into this stuff.

 

Ok, when you connect for the KOEO, and start the test, you should hear the fuel pump run twice, a buncha clicking and buzzing, and then you should see the codes start flashing (which you say the flashing is not occuring as I read it).

Did you hear any of the various noises described above? Also, after all the codes are done (assuming it is actually functional and running the tests), you can check the outputs by pressing the accelerator pedal (engine not running) to the floor. Each time WOT is detected, the ECM will toggle all the discrete outputs on and off, including the CEL. If you're not hearing the fuel pump run twice, or the clicking, the test is never starting. Make absolutely sure you're connecting the right pins on the connector if you're not using a plug-in reader. (I'm not saying you didn't, but I've been pretty sure of some things in my time, too, yet had to eat a little crow pie once in a while too) If the right pins are connected, and you don't get any activity in KOEO, the truck is only starting in limp mode with a dead ECM. They will crank and run, sometimes, albeit VERY poorly. If it's cranking and running good, then this suggests an error somewhere along the way in the testing. I did say suggests, not "means". The truck cannot possibly run good on a dead ECM. How's it running?

 

the Truck runs good better than it ever has the truck cycles and does all the cliking and cycling it sopose to just im using a code reader and im trying to jump it but both times dont work. cel comes on then off truck cycles and no flashing light just a littel srtange i think i have another ecu laying around il going to hook it up and see what happens.

 

update plugged up the old ecu and nothing happend truck just spun and spun no spark or any thing any way to test the ecu